diff --git a/arch/sparc/mm/sun4c.c b/arch/sparc/mm/sun4c.c
index 1d56039..731f196 100644
--- a/arch/sparc/mm/sun4c.c
+++ b/arch/sparc/mm/sun4c.c
@@ -497,7 +497,7 @@
 	patch_kernel_fault_handler();
 }
 
-volatile unsigned long *sun4c_memerr_reg = NULL;
+volatile unsigned long __iomem *sun4c_memerr_reg = NULL;
 
 void __init sun4c_probe_memerr_reg(void)
 {